The World Health Organization and the American Lung Association both report a growing trend in the use of water pipes for tobacco smoking by youth around the world and in the U.S.A. Water pipe smoking by adults has been shown to be associated with many of the same health problems that result from cigarette smoking, (e.g., poor lung function,malignant and non-malignant lung disease) but little is known about the health effects of water pipe smoking in adolescents. If early and potentially serious health effects can be identified in adolescence from water pipe smoking with or without cigarette smoking, the benefit to the public health message would be enormous. Spirometric measures of lung function provide an objective and noninvasive means to identify lung damage in adolescents. A few studies have reported impaired lung function in adolescent cigarette smokers but none have examined the health effects of water pipe smoking in adolescents. One cannot assume the lung and health consequences of water pipe and cigarette smoking are the same as they are performed in different ways with different doses and with different tobacco types. In addition, they produce different volumes of smoke, particulates, and nicotine. Our hypothesis is that WP smoking significantly diminishes lung function and contributes to general health problems in adolescents. Our corollary hypothesis is that adolescents who smoke the water pipe will show differing patterns, frequency, and intensity of product use, yet manifest similar or worse health problems than those found in cigarette smokers. The proposed three-year study will be conducted in three public high schools in southeastern Michigan. These schools were selected because our prior research found a high prevalence of water pipe smoking among students with Middle Eastern and non-Middle Eastern heritage. A detailed water pipe and cigarette smoking life time history of tobacco use will be obtained from 3000 high school seniors. The 300 students with the longest and most severe water pipe and/or cigarette smoking histories will be asked to participate in saliva cotinine testing (to verify their smoking status) and pulmonary function testing. These students will be compared with nonsmokers (n = 300) matched on key pulmonary function variables (age, gender, height, and ethnicity). The analyses will estimate the effects of smoking status on each of the spirometry outcomes (FEV1, FVC, FEV1/FVC, FEV25-75). We will determine the joint effect of smoking both water pipes and cigarettes and the independent effects of each. The relative effects of each type of smoking will be examined in a dose response analysis and by ranking the four smoking status groups on each of the spirometric parameters. Patterns and predictors of WP and cigarette smoking initiation and progression will be identified. PUBLIC HEALTH RELEVANCE: Water pipe smoking (WPS) is a very old tradition in the Middle East, North Africa, and Asia, which is now growing in use around the world and in the United States. It is especially dangerous for adolescents whose lungs are still developing. This study will examine the effects of adolescent WPS on lung function and general health. In addition, we will determine the patterns and predictors of this form of tobacco use.